pete williams, the big question at this moment, was there a foreign connection to terrorism? what do we know? >> well, we don't know the answer to that question. the big gap here is what was the older brother doing in russia for six months last year? he leaves in january, arrives in july, and the russians have told the fbi that they were a little worried about him. but what was he doing during all that time in russia? his father says he was visiting him, that he went to see his family, went to renew his russian passport while he was awaiting american citizenship. he was here as a lawful permanent resident. did he -- the thing i think that's the biggest question for investigators now is, "a," why did he turn this way? but, "b," where did he get his expertise in explosives? where did he practice them? it seems really unlikely these two bombs successfully were detonated without some practice runs. where did he learn to do that? where did he practice? those are the big questions. >> we look at the pictures of the suspects and biographical information we have, dzhokhar, who is the